Iwe waona kuti zvikamu zvakagadzirwa kune yakatarwa.Ikozvino ita shuwa kuti unotora matanho ekudzivirira aya zvikamu munzvimbo inotariswa nevatengi vako.#base
Passivation inoramba iri danho rakakosha mukuwedzera kuomarara kwezvikamu uye magungano akagadzirwa kubva kusimbi isina tsvina.Izvi zvinogona kuita mutsauko pakati pekuita kunogutsa uye kukundikana nguva isati yakwana.Kufamba kusina kunaka kunogona kukonzera ngura.
Passivation inzira yekumashure-yekugadzira iyo inokwidziridza iyo yekuzvarwa corrosion kuramba kwesimbi isina tsvina alloys kubva iyo workpiece inogadzirwa.Uku hakusi kudzikisira kana kupenda.
Iko hakuna kubvumirana pane chaiyo nzira iyo passivation inoshanda.Asi zvinonyatsozivikanwa kuti pane inodzivirira oxide firimu pamusoro pamusoro passivated Stainless simbi.Iri firimu risingaoneki rinonzi rakatetepa zvikuru, risingasviki 0.0000001 inch gobvu, iro rinenge 1/100,000th kukora kwebvudzi romunhu!
Yakachena, ichangobva kugadzirwa, yakakwenenzverwa, kana pickled Stainless simbi chikamu chinongowana iyi oxide firimu nekuda kwekusangana nemhepo yemhepo.Pasi pemamiriro akanaka, iyi inodzivirira oxide layer inovhara zvachose nzvimbo dzese dzechikamu.
Mukuita, zvisinei, zvinosvibisa zvakadai setsvina yefekitari kana simbi zvidimbu kubva kumidziyo yekucheka zvinogona kupinda pamusoro pezvikamu zvesimbi zvisina tsvina panguva yekugadzirisa.Kana isina kubviswa, miviri yekunze iyi inogona kuderedza kushanda kwefirimu yekudzivirira yepakutanga.
Munguva yekugadzira, mitsara yesimbi yemahara inogona kubviswa kubva pachishandiso uye ichiendeswa kumusoro kwesimbi isina tsvina workpiece.Mune zvimwe zviitiko, nhete yakatetepa yengura inogona kuonekwa pane chikamu.Kutaura zvazviri, uku ndiko kuora kwesimbi yemudziyo, kwete nheyo yesimbi.Dzimwe nguva kutsemuka kubva kune yakamisikidzwa simbi zvimedu kubva kukucheka maturusi kana zvigadzirwa zvavo zvekuora zvinogona kukanganisa chikamu chacho.
Saizvozvo, zvimedu zvidiki zve ferrous metallurgical tsvina zvinogona kunamatira kumusoro kwechikamu.Kunyange zvazvo simbi iyi inogona kuoneka ichipenya mukupera kwayo, mushure mekusangana nemhepo, zvimedu zvisingaoneki zvesimbi yemahara zvinogona kukonzera ngura pamusoro.
Akafumurwa sulfides anogonawo kuva dambudziko.Iwo anogadzirwa nekuwedzera sarufa kusimbi isina tsvina kuti uvandudze machinability.Sulfides inowedzera kugona kweiyo alloy kugadzira machipisi panguva yekugadzira, iyo inogona kubviswa zvachose kubva pachigadzirwa chekucheka.Kana zvikamu zvisina kufambiswa nemazvo, masulfide anogona kuve nzvimbo yekutangisa yekuora kwepasi kwezvigadzirwa zvemaindasitiri.
Muzviitiko zvose zviri zviviri, passivation inodiwa kuti uwedzere kupikisa kwechisikigo chekudzivirira kwesimbi isina tsvina.Inobvisa zvinosvibisa pamusoro senge iron particles uye iron particles mukucheka maturusi anogona kuita ngura kana kuva pekutangira kwekuora.Passivation inobvisawo sulfides inowanikwa pamusoro peakavhurika akachekwa Stainless simbi alloys.
Maitiro maviri-matanho anopa yakanyanya kunaka kushora: 1. Kuchenesa, iyo nzira huru, asi dzimwe nguva inoregeredzwa 2. Acid bath kana passivation.
Kuchenesa kunofanira kugara kuchikosha.Nzvimbo dzepamusoro dzinofanirwa kunyatsocheneswa girizi, inotonhodza kana mamwe madhiri kuti ive nechokwadi chekusaita ngura.Machining marara kana imwe tsvina yefekitori inogona kudzimwa zvinyoro nyoro kubva pachikamu.Commercial degreasers kana cleaners inogona kushandiswa kubvisa process oils kana coolants.Zvekune dzimwe nyika senge thermal oxides zvingada kubviswa nenzira dzakaita sekugaya kana kunhonga.
Dzimwe nguva mushandisi wemuchina anogona kusvetuka kucheneswa kwekutanga, achitenda zvisiri izvo kuti kuchenesa uye kufambisa zvichaitika panguva imwe chete, nekungonyudza chikamu chakazorwa muasidhi yekugezera.Hazvizoitiki.Sezvineiwo, girisi yakasvibiswa inopindirana neasidhi kuita mabhuru emhepo.Aya mabhuru anounganidza pane workpiece pamusoro uye anokanganisa passivation.
Zvakatonyanya kuipa, kusvibiswa kwemhinduro dze passivation, dzimwe nguva dzine huwandu hwakawanda hwekloridi, inogona kukonzera "flash".Kusiyana nekugadzira firimu rinodiwa reoxyde ine inopenya, yakachena, isingaite ngura, kupenya kwemwenje kunogona kuguma nekudzika kwakanyanya kana kusviba kwechiso-kushata kwepamusoro kunogadzirirwa kukwirisa.
Martensitic Stainless simbi zvikamu [magnetic, zvine mwero corrosion resistance, goho simba rinosvika 280 000 psi (1930 MPa)] inodzimwa patembiricha yakakwira uye yobva yadzikamiswa kuti ipe kuomarara kwaunoda uye michina yemagetsi.Kunaya kwakaomeswa ma alloys (ayo ane simba riri nani uye anodzivirira ngura pane martensitic mamakisi) anogona kugadziriswa mhinduro, kugadzirwa zvishoma, kuchembera pazasi tembiricha, uye yopera.
Muchiitiko ichi, chikamu chacho chinofanira kucheneswa zvakakwana ne degreaser kana kuchenesa kusati kwaitwa kupisa kubvisa chero maitiro ekucheka mvura.Zvikasadaro, inotonhorera yakasara pane iyo inogona kukonzera yakawandisa oxidation.Chirwere ichi chinogona kuita kuti mazino aumbe pazvikamu zvidiki mushure mekudonha neasidhi kana nzira dzekukwenya.Kana chinotonhodza chikasiiwa panhengo dzakaomeswa dzinopenya, senge muchoto chevacuum kana mumhepo inodzivirira, pamusoro pecarburization inogona kuitika, zvichikonzera kurasikirwa kwekushomeka kwecorrosion.
Mushure mekunyatsocheneswa, simbi isina tsvina inogona kunyudzwa mune passivating acid bath.Chero nzira nhatu idzi dzinogona kushandiswa - passivation ne nitric acid, passivation ne nitric acid ine sodium dichromate, uye passivation ne citric acid.Ndeipi nzira yekushandisa inoenderana negiredhi resimbi isina tsvina uye yakatsanangurwa maitiro ekugamuchira.
Mamwe magiredhi echromium asingadziviri kucorrosion anogona kupfuudzwa mu20% (v/v) nitric acid bath (Mufananidzo 1).Sezvinoratidzwa mutafura, simbi isina simbi isingadzivirirwe inogona kupfuudzwa nekuwedzera sodium dichromate mubhavhu renitric acid kuita kuti mhinduro yacho iwedzere oxidizing uye inokwanisa kugadzira firimu rinopfuura pamusoro pesimbi.Imwe sarudzo yekutsiva nitric acid nesodium chromate ndeyekuwedzera huwandu hwe nitric acid kusvika 50% nehuwandu.Kuwedzerwa kwesodium dichromate uye kuwanda kwe nitric acid kunoderedza mukana wekupenya kusingadiwe.
Iyo passivation nzira ye machinable Stainless steels (inoratidzwawo muFig. 1) yakasiyana zvishoma nemaitiro emhando dzisina machinable simbi isina tsvina.Izvi imhaka yokuti panguva passivation ari nitric asidhi kugeza zvimwe kana zvose machinable sarufa-ine sulfides anobviswa, zvichiita microscopic inhomogeneities pamusoro pemvura workpiece.
Kunyangwe kazhinji kugeza mvura kunoshanda kunogona kusiya yakasara asidhi mune izvi discontinuities mushure mekupfuura.Iyi asidhi inorwisa pamusoro pechikamu kana isina kuderedzwa kana kubviswa.
Kuti zvifambe zvakanaka zvesimbi isina tsvina iri nyore-ku-muchina, Carpenter akagadzira nzira yeAAA (Alkaline-Acid-Alkaline), iyo inoderedza yakasara asidhi.Iyi passivation nzira inogona kupedzwa mukati meawa isingasviki 2.Heino nhanho nhanho maitiro:
Mushure mekudzikisa, sora zvikamu mu 5% sodium hydroxide solution pa 160 ° F kusvika 180 ° F (71 ° C kusvika 82 ° C) kwemaminitsi makumi matatu.Zvadaro simbura zvikamu zvakakwana mumvura.Zvadaro nyudza chikamu kwemaminitsi makumi matatu mune 20% (v/v) nitric acid solution ine 3 oz/gal (22 g/l) sodium dichromate pa120°F kusvika 140°F (49°C) kusvika 60°C.) Mushure mokubvisa chikamu kubva mubhati, chisuke nemvura, wozochiisa mu sodium hydroxide solution kwemaminitsi makumi matatu.Shamba chikamu zvakare nemvura uye wooma, kupedzisa nzira yeAAA.
Citric acid passivation iri kuwedzera kufarirwa nevagadziri vanoda kudzivirira kushandiswa kwemamineral acids kana mhinduro dzine sodium dichromate, pamwe nezvinetso zvekurasa uye kuwedzera kunetseka kwekuchengetedza kunoenderana nekushandiswa kwavo.Citric acid inoonekwa seyakagadzikana mune zvese.
Nepo citric acid passivation ichipa inoyevedza mabhenefiti ezvakatipoteredza, zvitoro zvakave nebudiriro neinorganic acid passivation uye zvisina zvinetswa zvekuchengetedza zvinogona kuda kuramba zviriko.Kana vashandisi ava vaine chitoro chakachena, midziyo iri muchimiro chakanaka uye yakachena, inotonhorera haina fekitori ferrous deposits, uye maitiro ari kuburitsa mhedzisiro yakanaka, panogona kunge pasina kudiwa chaiko kwekuchinja.
Citric acid bath passivation yakawanikwa ichibatsira kune zvakasiyana-siyana zvesimbi dzisina tsvina, kusanganisira makirasi ega ega ega ega ega ega, sezvinoratidzwa mumufananidzo 2. Kuti zvive nyore, Mufananidzo 2. 1 inosanganisira nzira yechinyakare yekupfuura ne nitric acid.Ziva kuti maumbirwo ekare e nitric acid anotaridzwa sezvikamu nevhoriyamu, nepo iyo itsva citric acid mitsetse inoratidzwa sezvikamu nehukuru.Zvakakosha kuziva kuti kana uchiita maitiro aya, kunyatsogadzirisa nguva yekunyorova, tembiricha yekugezera, uye kuisa pfungwa kunokosha kuti udzivise "kupenya" kunotsanangurwa pamusoro apa.
Passivation inosiyana zvichienderana neiyo chromium yemukati uye maitiro ekugadzirisa ega ega.Cherechedzai makoramu eChirongwa 1 kana Maitiro 2. Sezvinoratidzwa mumufananidzo 3, Maitiro 1 ane matanho mashoma pane Maitiro 2.
Ongororo dzemuLabhoritari dzakaratidza kuti citric acid passivation process inowanzo "fashaira" pane iyo nitric acid process.Zvinhu zvinokonzeresa kurwiswa uku zvinosanganisira tembiricha yekugezera yakawandisa, nguva yakawandisa yekunyorova, uye kusvibiswa kwekugeza.Citric acid-yakavakirwa zvigadzirwa zvine corrosion inhibitors uye zvimwe zvinowedzera senge wetting agents zvinotengeswa uye zvinonzi zvinoderedza "flash corrosion" kubatwa.
Sarudzo yekupedzisira yepassivation nzira ichaenderana nemaitiro ekugamuchirwa akatarwa nemutengi.Ona ASTM A967 yeruzivo.Inogona kuwanikwa pawww.astm.org.
Miedzo inowanzoitwa kuti iongorore pamusoro pezvikamu zvakapfuura.Mubvunzo unofanirwa kupindurwa ndewekuti "Ko passivation inobvisa simbi yemahara uye inokwenenzvera kuramba kwecorrosion yealloys yekucheka otomatiki?"
Zvakakosha kuti nzira yekuedza ienderane nekirasi iri kuongororwa.Miedzo yakaomesesa haipfuure zvinhu zvakanaka chose, nepo bvunzo dzakanyanya kusimba dzinopfuura zvisingagutsi.
PH uye nyore-kugadzira 400 dzakatevedzana simbi dzisina tsvina dzinoongororwa zvakanyanya mukamuri inokwanisa kuchengetedza 100% mwando (sample wet) kwemaawa makumi maviri nemana pa95°F (35°C).Chikamu chemuchinjikwa kazhinji ndicho chinonyanya kukosha, kunyanya kune mahara ekucheka mamakisi.Chimwe chikonzero cheizvi ndechekuti sulfide inodhonzwa munzira yemuchina pane iyi nzvimbo.
Nzvimbo dzakakosha dzinofanirwa kuiswa kumusoro, asi pakona ye15 kusvika 20 madhigirii kubva pakatwasuka, kubvumira kurasikirwa nehunyoro.Zvinhu zvakafambiswa zvakanaka hazvizomboita ngura, kunyange zvazvo tuvara tuduku twunogona kuonekwa pachiri.
Austenitic Stainless simbi mamakisi anogonawo kuongororwa nekuongororwa hunyoro.Mumuedzo uyu, madonhwe emvura anofanira kunge aripo pamusoro pemuenzaniso, zvichiratidza simbi yakasununguka nekuvapo kwehupi hupi.
Passivation maitiro ezvinowanzo shandiswa otomatiki uye manyore masimbi asina tsvina mu citric kana nitric acid mhinduro inoda maitiro akasiyana.Pamusoro pemuonde.3 pazasi inopa ruzivo rwekusarudzwa kwemaitiro.
(a) Gadzirisa pH ne sodium hydroxide.(b) Ona muonde.3(c) Na2Cr2O7 is 3 oz/gal (22 g/L) sodium dichromate mu 20% nitric acid.Imwe nzira kune iyi musanganiswa ndeye 50% nitric acid isina sodium dichromate.
Nzira yekukurumidza ndeye kushandisa ASTM A380, Yakajairwa Dzidzira Yekuchenesa, Kubvisa, uye Passivation yeStainless Simbi Zvikamu, Equipment, uye Systems.Muedzo uyu unosanganisira kupukuta chikamu necopper sulfate/sulfuric acid solution, kuchichengeta chakanyorova kwemaminetsi matanhatu, uye kucherechedza kuputirwa kwemhangura.Neimwe nzira, chikamu chinogona kunyudzwa mune mhinduro kwemaminitsi matanhatu.Kana simbi ikanyunguduka, copper plating inoitika.Muedzo uyu haushande kunzvimbo dzekugadzira chikafu.Zvakare, haifanirwe kushandiswa pa400 akatevedzana martensitic simbi kana yakaderera chromium ferritic simbi sezvo mhedzisiro yenhema inogona kuitika.
Nhoroondo, iyo 5% yemunyu yekupfapfaidza bvunzo pa 95 ° F (35 ° C) yakashandiswawo kuongorora masampula akasiiwa.Muedzo uyu wakaomesesa kune mamwe ma cultivar uye kazhinji haudikanirwe kuratidza kushanda kwe passivation.
Dzivisa kushandisa ma chlorides akawandisa, izvo zvinogona kukonzera njodzi flare-ups.Shandisa mvura yemhando yepamusoro chete ine zvikamu zvisingasviki makumi mashanu pamiriyoni (ppm) chloride pese pazvinogoneka.Mvura yemupombi inowanzokwana, uye mune dzimwe nguva inogona kumira kusvika mazana ezvikamu pamamiriyoni emakloridi.
Zvakakosha kutsiva bhati nguva dzose kuitira kuti usarasikirwe nekugona kwepassivation, izvo zvinogona kutungamirira kukurohwa nemheni uye kukanganisa kwezvikamu.Iyo yekugezera inofanirwa kuchengetedzwa patembiricha yakafanira, sezvo tembiricha isingadzoreki inogona kukonzera ngura munzvimbo.
Izvo zvakakosha kuti uteedzere chaiyo chaiyo mhinduro shanduko chirongwa panguva yakakura yekugadzira inomhanya kuderedza mukana wekusvibiswa.Sample yekudzora yakashandiswa kuyedza kushanda kwebhati.Kana iyo muenzaniso yakarwiswa, inguva yekutsiva bhati.
Ndapota cherechedza kuti mimwe michina inongobudisa simbi isina tsvina;shandisa chitonhodzo chakafanana pakucheka simbi isina tsvina uchisiya mamwe simbi dzese.
Iyo DO rack zvikamu zvinogadzirwa zvakasiyana kudzivirira simbi kune simbi kusangana.Izvi zvinonyanya kukosha kune mahara machining eStainless simbi, sezvo nyore-kuyerera passivation uye flushing mhinduro zvinodiwa kuparadzira sulfide corrosion zvigadzirwa uye kudzivirira kuumbwa kweasidhi homwe.
Usapfuure carburized kana nitrided Stainless simbi zvikamu.Kupokana kwekuora kwezvikamu zvakabatwa nenzira iyi zvinogona kuderedzwa kusvika pamwero wakadaro zvekuti zvinogona kukuvadzwa mukugezesa passivation.
Usashandise ferrous metal zvishandiso mumamiriro emusangano asina kunyanya kuchena.Simbi machipisi anogona kudzivirirwa nekushandisa carbide kana ceramic maturusi.
Ziva kuti ngura inogona kuitika mukugezesa passivation kana chikamu chacho chisina kunyatsogadziriswa kupisa.Martensitic mamakisi ane yakakwira kabhoni uye chromium zvemukati zvinofanirwa kuomeswa kuti zvirambe corrosion.
Passivation inowanzoitwa mushure mekupisa kunotevera kune tembiricha inochengetedza corrosion resistance.
Usaregeredza kuwanda kwe nitric acid mukugezesa passivation.Kuongorora nguva nenguva kunofanirwa kuitwa pachishandiswa nzira yakapfava yekumisikidza yakataurwa naCarpenter.Usapfuure zvinopfuura simbi isina tsvina panguva.Izvi zvinodzivirira kuvhiringidzika kunodhura uye kudzivirira galvanic reactions.
NezveVanyori: Terry A. DeBold iStainless Steel Alloys R&D Nyanzvi uye James W. Martin iBar Metallurgy Nyanzvi paCarpenter Technology Corp.(Kuverenga, Pennsylvania).
Imarii?Ndinoda nzvimbo yakawanda sei?Ndedzipi nyaya dzezvakatipoteredza dzandichasangana nadzo?Ko kukwirira kwakadii?Chii chaizvo chinonzi anodizing?Pazasi pane mhinduro kumibvunzo yekutanga yevatenzi nezve anodizing mukati.
Kuwana anowirirana, emhando yepamusoro mhedzisiro kubva kucenterless kugaya maitiro kunoda nzwisiso yekutanga.Mazhinji ematambudziko ekushandisa ane hukama nepakati pekugaya anomuka kubva mukusanzwisisa kwezvakakosha.Ichi chinyorwa chinotsanangura kuti sei maitiro asina pfungwa achishanda uye mashandisiro aungaite zvakanyanya muwekishopu yako.